This invention is related in general to manufacturing, and in particular to a non-biological self replicating manufacturing system.
A recognized desire exists in the prior art for non-biological self replicating manufacturing systems. Manufacturing systems are commonly implemented to produce (or manufacture) many types of non-biological items, including but not limited to commercial products (e.g., automobiles, clothing, appliances, computer components, etcetera), industrial products (e.g., parts used in industrial factories), and even information (e.g., data generated by a computer system). Various attempts and advances have been made in such non-biological manufacturing systems of the prior art to manufacture an end product in a timely and cost efficient manner. A relatively simple example of a prior art manufacturing advancement was the development of the assembly line in the early 1900""s by Henry Ford to enable mass production of automobiles in a timely and cost efficient manner. Of course, numerous additional advances have been made in the field of manufacturing in attempts to further improve the timeliness and cost efficiency of various manufacturing systems.
While many such advancements have been made toward improving manufacturing systems"" production of an end product, a desire has also been recognized for improving the development of the manufacturing systems themselves. For example, a desire has been recognized for improving the timeliness and cost efficiency associated with developing (or xe2x80x9cmanufacturingxe2x80x9d) a manufacturing system. For instance, a factory may be implemented with one or more assembly lines included therein to enable the factory to mass produce automobiles. However, a desire exists for manufacturing the factory itself (having the assembly lines therein) in a timely and cost efficient manner. Prior art theorists have long recognized the desirability of a non-biological self replicating manufacturing system. Such a self replicating system would first enable a manufacturing system to effectively replicate, resulting in additional like manufacturing systems. Thereafter, the manufacturing systems may all work to manufacture end products. As a result, the timeliness and cost efficiency of producing a manufacturing system, as well as end products, may be enhanced.
As a broad example of such a self replicating theory, further consider the above example of a factory that includes assembly lines for mass producing automobiles. If such a factory were a self replicating manufacturing system, then the factory itself could produce another like factory (i.e., replicate), and the two factories could then work in parallel to manufacture end products (e.g., automobiles). Of course this theory need not only be applied at the highest level of a manufacturing system (e.g., the factory itself), but could be applied to any level within a manufacturing system (e.g., to any manufacturing system included within the factory). For example, an assembly line included within the factory, if implemented as a self replicating assembly line, could replicate to efficiently generate a desired number of such assembly lines to be utilized within the factory.
Self replication is a desirable concept not only for large scale manufacturing systems, such as factories, but also for much smaller scale manufacturing systems. A particular need has been recognized for a non-biological self replicating manufacturing system in the field of nanotechnology. That is, a particular need has been recognized for a non-biological self replicating manufacturing system for micro-assembly and nano-assembly of end products. For example, due to the particular complexity and time requirements typically associated with nanotechnology manufacturing, a non-biological self replicating manufacturing system in this field is especially desirable. In the past few decades, theories have been proposed for providing self replicating manufacturing systems on various size scales, from very large manufacturing systems (e.g., see the Lunar Factory proposed by NASA and ASEE described below) to manufacturing systems that manufacture end products at the molecular level (e.g., see Drexler""s Assembler described below).
One example of a proposed self replicating manufacturing system in space exploration is the Self-Replicating Lunar Factory proposed by the National Aeronautics and Space Administration (NASA) and the American Society for Engineering Education (ASEE) in 1980 (see NASA Conference Publication 2255: Advanced Automation for Space Missions, edited by Robert A. Freitas, Jr. and William P. Gilbreath, National Technical Information Service, U.S. Department of Commerce, Springfield, VA; N83-15348). This proposal describes a vastly complex self replicating system intended to self replicate within a relatively uncontrolled environment (i.e., the surface of the Earth""s moon). More specifically, the resulting proposal included a 150-page chapter on xe2x80x9cReplicating Systems Concepts: Self-Replicating Lunar Factory and Demonstrationxe2x80x9d which proposed a 20-year program to develop a self-replicating general purpose lunar manufacturing facility (a Self Replicating System, or SRS) that would be placed on the lunar surface. The initial xe2x80x9cseedxe2x80x9d for the facility, to be landed on the lunar surface from Earth to start the process, was 100 tons (approximately four Apollo missions). Once this 100-ton seed was in place, all further raw materials would be mined from the lunar surface and processed into the parts required to extend the SRS. A significant advantage of this approach for space exploration would be to reduce or eliminate the need to transport mass from the Earthxe2x80x94which is relatively expensive.
The report remarks that xe2x80x9c[t]he difficulty of surmounting the Earth""s gravitational potential makes it more efficient to consider sending information in preference to matter into space whenever possible. Once a small number of self-replicating facilities has been established in space, each able to feed upon nonterrestrial materials, further exports of mass from Earth will dwindle and eventually cease. The replicative feature is unique in its ability to grow, in situ, a vastly larger production facility than could reasonably be transported from Earth. Thus the time required to organize extraordinarily large amounts of mass in space and to set up and perform various ambitious future missions can be greatly shortened by using a self-replicating factory that expands to the desired manufacturing capacity.xe2x80x9d Accordingly, a large-scale, vastly complex, non-biological self replicating manufacturing system has been proposed in the prior art for operation within the relatively uncontrolled environment of the Earth""s moon. While such a system has been proposed, it has yet to be implemented in a manner that supports the proposition that such a vastly complex system is workable/successful as a self replicating manufacturing system in such an uncontrolled environment. Without such an implementation, such a proposal appears speculative due to the enormous complexity involved, in addition to the relatively unpredictable nature of the uncontrolled environment in which the manufacturing system is proposed to be implemented.
Another example of a proposed non-biological self replicating manufacturing system is provided in the theoretical work of von Neumann (see Theory of Self-Reproducing Automata, by John von Neumann, edited and completed by Arthur W. Burks, University of Illinois Press, 1966). The von Neumann architecture for a self replicating system is perhaps the ancestral and archetypical proposal for non-biological self replicating manufacturing systems (see e.g. How a SIMD machine can implement a complex cellular automaton?[sic] A case study: von Neumann ""s 29-state cellular automaton, by Jacqueline Signorini, Proceedings Supercomputing ""89, ACM Press, 1989). Von Neumann proposed two types of systems: (1) a cellular automata system and (2) a xe2x80x9ckinematic machine.xe2x80x9d
Von Neumann""s proposed self-replicating system consisted of two central elements: a Universal Computer and a Universal Constructor. The Universal Computer contains a program that directs the behavior of the Universal Constructor. The Universal Constructor, in turn, is used to manufacture both another Universal Computer and a Universal Constructor. Once constructed, the newly manufactured Universal Computer was programmed by copying the program contained in the original Universal Computer, and program execution would then begin on the newly manufactured Universal Computer.
Von Neumann worked out the details for a Constructor that worked in a theoretical two-dimensional cellular automata world, and parts of his proposal have since been modeled computationally (see How a SIMD machine can implement a complex cellular automaton?[sic] A case study: von Neumann""s 29-state cellular automaton, by Jacqueline Signorini). The Constructor had an arm, which it could move about; and a tip, which could be used to change the state of the cell on which it rested. Thus, the proposal suggested that by progressively moving the arm and changing the state of the cell at the tip of the arm, it was possible to create xe2x80x9cobjectsxe2x80x9d that consisted of regions of the two-dimensional cellular automata world which were fully specified by the program that controlled the Constructor. Theoretically, one such xe2x80x9cobjectxe2x80x9d that could be created by the Constructor is a like Constructor and companion computer.
While this solution demonstrates the theoretical validity of the idea, von Neumann""s kinematic constructor (which was not worked out in such detail) has had perhaps a greater influence, for it is a model of self replication which can more easily be adapted to the three-dimensional world in which we live. The kinematic constructor was a robotic arm which moved in three-space, and which grasped parts from a sea of parts around it. These parts were then assembled into another kinematic constructor and its associated control computer.
It should be noted that self replication, while important, is generally not a sole objective. A manufacturing device able to make copies of itself but unable to make anything else (or perform/satisfy some other task/function) would typically not be very valuable. Von Neumann""s proposals are centered around the combination of a Universal Constructor, which could make anything it was directed to make, and a Universal Computer, which could compute anything it was directed to compute. This combination provides immense value, for it can be re- programmed to make any one of a wide range of things. It is this ability to make almost any structure that is generally desired, and to do so at low cost, which is generally considered to be of value. The ability of the device to make copies of itself is typically a means to achieve low cost, rather than an end in itself. Of course, it is not a requirement that a self replicating manufacturing system be capable of producing an end product other than a like manufacturing system in order to have value. For example, a chair that is capable of replicating (or xe2x80x9cmanufacturingxe2x80x9d) itself but unable to manufacture any other end product is still valuable in that the chair itself, once produced, serves a useful function (i.e., provides a suitable surface for sitting).
A more recent proposal for a non-biological self replicating system has been presented by Eric Drexler for an xe2x80x9cassemblerxe2x80x9d (see Nanosystems: molecular machinery, manufacturing, and computation, by K. Eric Drexler, Wiley 1992). Drexler""s assembler follows the von Neumann kinematic architecture, but is specialized for dealing with systems made of atoms. That is, the emphasis of Drexler""s proposal (in contrast to von Neumann""s proposal) is on small size, e.g., molecular scale systems. In Drexler""s proposal, von Neumann""s computer and constructor both shrink to the molecular scale, while the constructor takes on additional detail consistent with the desire to manipulate molecular structures with atomic precision.
The molecular constructor of Drexler""s assembler has two major subsystems: (1) a positional capability and (2) the tip chemistry. The positional capability might be provided by one or more small robotic arms, or alternatively might be provided by any one of a wide range of devices that provide positional control (see e.g. Robotic Engineering: an Integrated Approach, by Richard D. Klafter, Thomas A. Chmielewski, and Michael Negin, Prentice Hall 1989). The emphasis, though, is on a positional device that is very small in scale: perhaps 0.1 microns (100 nanometers) or so in size. It should be understood, that in the field of nanotechnology, current Scanning Probe Microscope (SPM) designs typically employ piezoelectric elements for positional control (see e.g., Scanning Tunneling Microscopy and Atomic Force Microscopy: Application to Biology and Technology, by P. K. Hansma, V. B. Elings, O. Marti and C. E. Bracker, Science, Vol. 242, Oct. 14, 1988, pages 209-216). It has been recognized that, in general, it is more preferable to implement mechanical positioning systems having a large range of motion in relation to their overall size within a self replicating manufacturing system, in contrast to available piezoelectric or other electrostatic positioning devices having a small range of motion in relation to their overall size. In general, the reasons for such preference for mechanical positioning devices at the molecular scale are similar to the reasons that mechanical devices are commonly employed at the macroscopic scale: the desire for compactness, large range of motion relative to size, and high positional accuracy (e.g., high stiffness). These considerations weigh against electrostatic and piezoelectric devices. Molecular mechanical devices, on the other hand, can theoretically employ very stiff materials and, with appropriate design, can have joints that rotate easily but which at the same time provide high stiffness in other degrees of freedom (see e.g., Nanomachinery: Atomically precise gears and bearings, by K. Eric Drexler, in IEEE Micro Robots and Teleoperators Workshop, Hyannis, Cape Cod, November 1987; and A Proof About Molecular Bearings, by Ralph C. Merkle, Nanotechnology Volume 4, 1993, pages 86-90).
The tip chemistry in Drexler""s proposal is logically similar to the ability of the von Neumann universal constructor to alter the state of a cell at the tip of the arm, but now the change in xe2x80x9cstatexe2x80x9d corresponds to a real-world change in molecular structure. That is, a set of well-defined chemical reactions that take place at the tip of the arm must be specified, and this well-defined set must be sufficient to allow the synthesis of the class of structures of interest. Various methods for implementing such a xe2x80x9ctip chemistryxe2x80x9d have been proposed in the prior art. For example, Chemical Vapor Deposition (CVD) is often utilized for synthesizing diamond at a relatively low temperature and pressure. In this process a highly reactive low-pressure gas is passed over the growing diamond surface. The gas typically includes atomic hydrogen and various species of hydrocarbons. The growing diamond surface is usually terminated with hydrogen. A fairly common mechanism for growth involves (1) the abstraction of one or more hydrogen atoms from the surface, leaving one or more dangling bonds, followed by (2) reaction of the dangling bond(s) with a carbon containing species (e.g., CH3, C2H2, etc). This cycle of abstraction and deposition may be repeated indefinitely.
However, to make an atomically precise diamondoid structure, it would typically be undesirable to rely on reactive molecules in a gas. A gas molecule can react with the surface at any location, and so the synthesis process is statistical and largely uncontrolled. To achieve atomically precise control over the product, highly precise positional control over the reactants is generally needed. One suggestion in the prior art is to mount a highly reactive molecule on the tip of a positional device. For example, hydrogen abstraction can take place when an atomic hydrogen in the reactive gas strikes a hydrogen bonded to the growing surface. In some cases, the result will be an H2 molecule leaving the surface and a dangling bond at the site where the H was removed. Unfortunately, atomic hydrogen is difficult to hold without making it inert. Bonded to the tip of a positional device, a hydrogen atom is non-reactive. If it is not bonded to some structure, then it is difficult to control its position with the required precision. Thus, the prior art has proposed a hydrogen abstraction tool which (a) has one end which is fairly stable, and so can be bonded into a larger xe2x80x9chandle,xe2x80x9d and (b) has a highly reactive end that has a high affinity for hydrogen.
An example of such a prior art tool is the propynyl hydrogen abstraction tool illustrated in FIG. 1. In the exemplary theory of the prior art shown in FIG. 1, the carbon atom at the tip is triply bonded to the middle carbon atom, which is in turn singly bonded to the carbon atom at the base. The tip atom is a radical. If the tip atom were bonded to hydrogen, the resulting bond would be very strong: about 130 kcal/mole. Quantum chemical calculations strongly support the idea that this tool will be able to easily abstract hydrogen from most diamond surfaces, and in particular that the barrier to the abstraction will either be small or non-existent (see e.g., Theoretical Studies of a Hydrogen Abstraction Tool for Nanotechnology, by Charles B. Musgrave, Jason K. Perry, Ralph C. Merkle and William A. Goddard, III, Nanotechnology 2, 1991, pages 187-195). The base of the tool would be bonded into an extended diamondoid xe2x80x9chandlexe2x80x9d which could then be mechanically grasped and positioned. This tool could be used to remove hydrogen in a site-specific fashion from a diamondoid work-piece, thus setting the stage for a carbon deposition tool to bond one or more carbon atoms at that site. Once the tool had performed its task it could either be thrown out and a new tool created from an appropriate pre-cursor, or the tool could be xe2x80x9crefreshedxe2x80x9d by removal of the abstracted hydrogen atom.
Additionally, several proposals for carbon deposition tools have been made. The general idea, however, is to use tools which bond a gas-phase growth species to a positionally controlled tip, and then to employ a reaction mechanism similar to that which would occur for the gas-phase species during deposition on the surface. It is useful to note that positional control also provides a convenient and very controlled mechanism for providing the activation energy sometimes needed: it is possible to apply mechanical force (push). This option is not normally available in chemistry and so opens up a rich new set of reaction mechanisms.
The assembler, as proposed by Drexler, is not a specific device, but is instead a class of devices. Specific members of this class will deal with specific issues in specific ways. Accordingly, it has been suggested in the prior art, that to enable such an assembler as that proposed by Drexler, one is required to specify many details of such assembler (see Self Replicating Systems and Molecular Manufacturing, by Ralph C. Merkle, Journal of the British Interplanetary Society, Volume 45, 1992, pages 407-413). For example, to specify an assembler one needs to specify (1) the type and construction of the computer, (2) the type and construction of the positional device, (3) the set of chemical reactions that take place at the tip, (4) how compounds are transported to and from the tip, and how the compounds are modified (if at all) before reaching the tip, (5) the class of structures that can be built by the assembler, (6) the environment in which it operates, and (7) the method of providing power to the assembler. Additionally, it has been recognized that it is often desirable to be capable of transmitting instructions to the assembler. Therefore, an additional element may be required to be specified: (8) a receiver that allows the assembler to receive instructions (e.g., broadcast instructions, as discussed more fully below). Depending on the type of manufacturing system desired, as well as the environment in which such system is expected to function, additional characteristics may need to be specified for the assembler.
Another type of theoretical non-biological self replicating system, also proposed in the prior art, is Richard Laing""s replication by inspection approach (see Some Alternative Reproductive Strategies in Artificial Molecular Machines, Journal of Theoretical Biology, Volume 54, 1975, pages 63-84; Automation Introspection, Journal of Computer System Science, Volume 13, 1976, pages 172-183; and Automation Models of Reproduction by Self-Inspection, Journal of Theoretical Biology, Volume 66, 1977, pages 437-456; by Richard A. Laing). This approach relies upon the ability, in von Neumann""s kinematic model, of a machine to identify all parts of the system and thus to determine the type and location of all components. Thus for example, a replicating system may consist of two devices-one active, the other passive, but each capable of assuming passivity upon a signal from the active device. Beginning with two devices (not necessarily identical), one device inspects the second device and builds a duplicate of the second device. Then the second device inspects the first and builds a duplicate of it, the active and passive status of the two devices being exchanged. The result is that the two devices have replicated themselves, without either device being independently capable of self-replication, but also without either device possessing any explicit set of structural plans.
A further type of non-biological self replicating system has been proposed in the prior art, which utilizes a xe2x80x9cbroadcast architecture.xe2x80x9d In the von Neumann architecture and Drexler""s assembler (and in living systems) the complete set of plans for the system are carried internally in some sort of memory. This is not a logical necessity in a self replicating manufacturing system. If the xe2x80x9cconstructorxe2x80x9d is separated from the xe2x80x9ccomputer,xe2x80x9d and many individual constructors are allowed to receive broadcast instructions from a single central computer then each constructor need not remember the plans for what it is going to construct: it can simply be told what to do as it does it. An example of such a broadcast architecture is illustrated logically in FIG. 2. As shown in FIG. 2, a central macroscopic computer 202 may be implemented, which broadcasts instructions to one or more molecular constructors 204. This approach not only eliminates the requirement for a central repository of plans within the constructor (which is now the component that self replicates), it can also eliminate almost all of the mechanisms involved in decoding and interpreting those plans. Advantages of such a broadcast architecture include: (1) it reduces the size and complexity of the self replicating component, (2) it allows the self replicating component to be rapidly redirected to build something novel, and (3) if the central computer is macroscopic and directly controllable, the broadcast architecture is inherently xe2x80x9csafexe2x80x9d in that the individual constructors lack sufficient capability to function autonomously (e.g., prevents constructors from replicating on their own undesirably).
Various methods have been proposed for enabling such a xe2x80x9cbroadcast architecture.xe2x80x9d Drexler has proposed immersing the constructor in a liquid or gas capable of transmitting pressure changes and using pressure sensitive ratchets to control the motions of the constructor. If each pressure sensitive ratchet has a distinct pressure threshold (so that pressure transitions around the threshold cause the ratchet to cycle through a sequence of steps while pressure changes that remain about or below the threshold cause the ratchet to remain inoperative) then it is possible to address individual ratchets simply by adjusting the pressure of the surrounding fluid. This greatly reduces the complexity of the instruction decoding hardware. This general approach is similar to that taken in the Connection Machine (see The Connection Machine, by Daniel Hillis, MIT Press, 1986) in which a single complex central processor decodes and broadcasts instructions to a large number of very simple processors with limited memory and limited capabilities. Storing the program, decoding instructions, and other common activities are the responsibility of the single central processor; while the large number of small processors need only interpret a small set of very simple instructions. Thus, this xe2x80x9cbroadcastxe2x80x9d approach may minimize the amount of memory required for each assembler. On the other hand, if the assembler were not able to receive broadcast instructions, then it would be necessary for each assembler to have sufficient on-board memory to remember (a) how to build a second assembler and (b) how to build some useful product (or perform some other useful task once it is completed). In this scenario, a single appropriately programmed xe2x80x9cseedxe2x80x9d assembler would then have to replicate itself, manufacturing a large number of similarly programmed copies of itself. Accordingly, such an approach is less economically desirable than a broadcast approach.
It is important to note that the particular focus herein is directed toward xe2x80x9cnon-biologicalxe2x80x9d self replicating manufacturing systems (which may also be referred to herein as xe2x80x9cgeneral manufacturing systemsxe2x80x9d). Many biological systems are available that are capable of self replication (e.g., human beings, etcetera). Such biological systems commonly include the ability for self replication. However, non-biological manufacturing systems (e.g., factories) are typically unable to self replicate. Many differences have been noted in the prior art between non-biological self replicating manufacturing systems, to which the present application is directed, and biological systems. While a non-biological self replicating system may be implemented in a manner that models (or simulates) a biological system, non-biological self replicating systems remain very different than a biological system. For example, just as an airplane is modeled in some respects after a bird, while remaining much different than a bird, a non-biological self replicating system may model a biological system but remain very different than a biological system.
While the benefits of implementing a self-replicating manufacturing system have been long recognized (see e.g., There""s Plenty of Room at the Bottom, by Richard P. Feynman, Caltech""s Engineering and Science, February 1960, which recognizes a desire for a set of slave xe2x80x9chandsxe2x80x9d that are somehow operable to manufacture smaller copies of such xe2x80x9chandsxe2x80x9d), little advancement has been made beyond the above prior art theories that have been proposed. That is, beyond the theories proposed for non-biological self replicating systems, little advance has been made in the prior art toward implementation of a non-biological self replicating system, particularly within the field of nanotechnology. Micro-assembly manufacturing stations of the prior art are typically developed one at a time by an outside manufacturing source (i.e., are not self-replicating). Furthermore, prior art micro-assembly manufacturing stations are typically manufactured either sequentially or in parallel with one another. One problem in prior manufacturing techniques is that generally an essential component of building more manufacturing systems is human involvement. People are commonly required to perform one or more critical operation(s) in the micro-assembly of a manufacturing station.
One example of a massively parallel technique commonly utilized in prior art micro-mechanical or micro-electrical manufacturing is that of lithography. Lithography is a well-known manufacturing technique that is very parallel in nature in that it may be utilized to process millions of devices simultaneously, but it is a technique which is not self replicating. Lithography is external to the manufactured parts themselves, e.g., the parts manufactured using lithography are not capable of further lithography of like parts. Thus, while lithography enables massive parallelism in manufacturing components, it does not enable self replication. Various manufacturing techniques have been developed in the prior art to enable massive parallelism in the manufacture of such parts; however, a successful self replicating manufacturing system for micro-assembled parts has not been developed in the prior art. While massive parallelism in manufacturing generally increases the efficiency of the manufacturing system beyond sequential manufacturing, parallel manufacturing does not achieve the level of efficiency that may be achieved through self replication of a manufacturing system.
A non-biological self replicating manufacturing system is desirable for many reasons. First, self replication is an effective route to truly low cost manufacturing. Furthermore, self replication may enable manufacturing to be accomplished in a timely manner, e.g., decrease the overall time required to manufacture a resulting product. Additionally, self replication may enable a precise manufacturing process having a small rate of error. For example, self replication can all but eliminate the presence of xe2x80x9chuman errorxe2x80x9d (or other xe2x80x9coutside manufacturing sourcexe2x80x9d error) that is commonly introduced into the manufacturing process.
In view of the above, a desire exists for a non-biological self replicating manufacturing system. A particular desire exists for a non-biological self replicating manufacturing system for performing small scale assembly, such as micron-scale and nanometer-scale assembly. A further desire exists for a non-biological self replicating manufacturing system that enables many assembly stations to be constructed in an efficient manner.
These and other objects, features and technical advantages are achieved by a system and method which provide a non-biological self replicating manufacturing system (xe2x80x9cSRMSxe2x80x9d). A preferred embodiment provides an SRMS that enables assembly stations to replicate (i.e., construct like assembly stations). In a preferred embodiment, positional assembly is utilized by one or more assembly stations to construct like assembly stations. Furthermore, in a most preferred embodiment, such assembly stations are small scale devices that are capable of working with small scale parts in order to construct like assembly devices. For example, such assembly stations may be micron-scale devices that are capable of constructing like assembly devices from micron-scale parts. Of course, in alternative embodiments such assembly stations may be larger scale devices.
A preferred embodiment provides an SRMS in which surface-to-surface assembly is performed. That is, an assembly station on a first surface, Surface A, constructs a like assembly station on another surface, Surface B. Such construction is preferably accomplished through positional assembly. Accordingly, the parts necessary to construct a like assembly station are prearranged in an accurate manner (within some acceptable degree of positional error) on Surface B, and are presented to the assembly station of Surface A. For example, each surface may be a wafer that contains one or more die sites on which the necessary parts are prearranged. In a preferred embodiment, the two surfaces are handled by a translating machine of the SRMS, which positions the assembly station of Surface A across from the parts of Surface B. Instructions are then sent (e.g., from a control computer) to the assembly station to cause the assembly station to construct a like assembly station from the prearranged parts on Surface B. Accordingly, a preferred embodiment provides an SRMS in which one or more assembly stations may be constructed by a like assembly station.
In a most preferred embodiment the SRMS is implemented such that the construction of like assembly stations (i.e., the replication of assembly stations) is accomplished in an efficient manner. For example, parts necessary for constructing assembly stations may be included on both Surface A and Surface B, and assembly stations on each surface may construct like assembly stations on the other surface. For instance, assembly stations on Surface A may construct like assembly stations on Surface B, while assembly stations on Surface B may construct like assembly stations on Surface A. Such construction may be performed in a ping-pong manner between the two surfaces. Alternatively, such construction may be performed in parallel on the surfaces, wherein assembly stations on Surface A construct like assembly stations on Surface B while assembly stations on Surface B simultaneously construct like assembly stations on Surface A. Various other assembly processes may be implemented in the SRMS of a preferred embodiment. Most preferably, the assembly stations replicate at an exponential rate. For instance, in one embodiment the assembly stations replicate according to a Fibonacci sequence. In another embodiment the assembly stations replicate exponentially in a manner such that n replication iterations result in assembly stations on the order of 2n, i.e., xe2x80x9cO(2n)xe2x80x9d assembly stations.
Accordingly, in a most preferred embodiment, once one or more assembly stations are constructed, such assembly stations may be presented the necessary parts and instructions to self replicate. Additionally, once one or more assembly stations are constructed, such assembly stations are most preferably capable of performing at least one other task (beyond self replicating). For example, in a most preferred embodiment, such one or more assembly stations may be presented with the necessary parts and instructions to enable such assembly stations to assemble a different device (e.g., a non-like device) or perform some other function.
It should be understood that a preferred embodiment may provide a general manufacturing system that is capable of assembling a specific manufacturing system. Such specific manufacturing system may be identical to the general manufacturing system (i.e., may in effect be another xe2x80x9cgeneral manufacturing systemxe2x80x9d), or it may be different from the general manufacturing system. For example, the SRMS of a preferred embodiment may be implemented to enable multi-generational growth of assembly stations, in which a first generation of assembly station(s) assemble a second (or xe2x80x9claterxe2x80x9d) generation of assembly stations. Thereafter, such later generation of assembly stations may further assemble even later generation of assembly stations, and so on. It should be understood that the assembly stations of each generation may be identical. However, in some implementations the assembly stations of each generation may be xe2x80x9clikexe2x80x9d assembly stations that are not necessarily identical. For example, the size of one or more generations of assembly stations may differ from that of the earlier generations. For instance, a first generation may assemble a second generation of assembly stations that are downscaled or upscaled from the first generation. As another example, the assembly stations of one or more later generations may be completely different than the earlier generations of assembly stations.
Furthermore, it should be recognized that each assembly station may actually comprise multiple assembly stations (or xe2x80x9csub-assembly stationsxe2x80x9d), which each assemble a portion of another assembly station. For instance, a first assembly station may comprise two sub-assembly stations, A and B. Sub-assembly station A may function to assemble a subassembly station B on a facing surface, and sub-assembly station B may function to assemble a sub-assembly station A on such facing surface, thereby resulting in a second assembly station that comprises sub-assembly stations A and B. For example, an SRMS may consist of a set of two or more assembly stations of non-like types which may cooperatively replicate a similar set using a sequence of surface-to-surface manufacturing operations, a process which may be called non-singlet replication. By way of illustration, and without intending to preclude other implementations from the scope of the present invention, consider a set consisting of an assembly station of type A and a second assembly station of type B. The initial stations A and B may be manually constructed (e.g., hand-built). On an opposing surface, station A may then construct 50% of a xe2x80x9cdaughter stationxe2x80x9d A, while station B constructs a different 50% of daughter station B. Thereafter, station B may be used to construct the remaining 50% of daughter station A, while station A constructs the remaining 50% of daughter station B, thereby completing the construction of both daughter assembly stations. Thus in non-singlet replication, assembly stations A and B might not be able independently to self-replicate, but the set (consisting of A plus B) can self-replicate additional like sets exponentially.
Thus, a most preferred embodiment provides a manufacturing system that utilizes surface-to-surface assembly. Furthermore, such manufacturing system may perform the surface-to-surface assembly in a parallel manner (e.g., more than one surface-to-surface assembly may be performed simultaneously). Further still, such a surface-to-surface assembly may be implemented in a ping-pong manner to construct assembly stations on two or more surfaces in an efficient manner. Additionally, a most preferred embodiment provides such a surface-to-surface assembly that may be implemented for small scale assembly (e.g., assembly on the micron scale). It should also be noted that a most preferred embodiment implements one or more surfaces, which may each comprise one or more assembly stations thereon, such that common translational movements are utilized for such one or more surfaces, thereby enabling the one or more assembly stations thereon to be simultaneously translated in a common manner. A most preferred embodiment enables surface-to-surface manufacturing to be extended to three dimensions by stacking multiple surfaces (or xe2x80x9cwork areasxe2x80x9d). As discussed in greater detail below, a preferred embodiment provides a positional assembly manufacturing system that presents appropriate parts prearranged on wafers (or some other type of surface-mounted parts holders) to an assembly station, which then assembles the parts on the wafer (or other surface). Further still, in a most preferred embodiment such parts may be micron-scale parts (e.g., MEMS parts produced using lithographic, integrated-circuit based production methods). In a most preferred embodiment, a manufacturing station having two degrees of rotational freedom (referred to herein as a xe2x80x9cMS2Rxe2x80x9d), as described herein, is implemented as the assembly station within the SRMS. However, in alternative embodiments, any type of assembly station capable of self replication may be implemented within the SRMS.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.